Burners for vaporised fuel



Sept. 22 1959 A. G. IMBER ET AL 2,905,233

BURNERS FOR VAPORISED FUEL Filed Jan. 31, 1955 INVENTOR ALFRED G. [MBER ALF/2E0 HALL.

ATTORNEYS 2,905,233 Patented Sept. 22, 1959 2,905,233 BURNERS FOR VAPORISED FUEL Alfred G. Imber, London, and Alfred Hall, Greenford,

England, assignors to Imber Research Limited, Greenford, England, a British company Application January 31, 1955, Serial No. 485,204

Claims priority, application Great Britain February 3, 1954 1 Claim. (Cl. 158-531) This invention relates to burners for vaporised fuel and has particular reference to burners used in pressure lamps or lanterns, cookers and heaters, wherein the fuel is caused to ascend from a reservoir maintained under pressure and pass through a vaporiser tube to a jet orifice and mixing chamber to the burner. In lamps or lanterns of this kind it is well known to provide a hand-operable cleaning needle for the jet orifice and whilst with certain types of fuels, this needle sufiices to enable the jet orifice to be cleared of deposits, additional difiiculties have been created by the deposits from certain liquid fuels, such as leaded petrol which when vaporised forms solid deposits in the nature of gum or lead compounds which tend to flake away from the walls of the vaporiser and obstruct the jet.

The object of the present invention is to provide an improved construction or arrangement applicable to the vaporiser of a pressure burner and designed to enable leaded petrol or similar fuel to be burnt satisfactorily in a pressure lantern by entrapping solid particles and the like and preventing them from reaching the jet orifice.

According to the invention a vaporiser for a pressure burner of the kind referred to is provided throughout its internal height with a number of spaces wherein decomposition of the fuel by vaporisation takes place, such spaces alternating with zones of filtering media which entrap solid particles which would otherwise travel up the vaporiser with the fuel and obstruct the jet.

An embodiment of the invention will now be described with reference to the accompanying drawing of a vaporiser, shown partly in section.

In the drawing, the tubular vaporiser 1 is arranged in known manner for detachable connection at its base 2 to a reservoir (not shown) constructed to contain liquid fuel under pressure and is formed at its upper end with a cap 3 having a central jet orifice 4 adapted to be cleared by means of a needle 5 movable axially within the vaporiser by hand operation when required. A suitable fuel inlet opening 11 is provided through base 2. Disposed within the vaporiser tube 1 and concentrically surrounding the cleaning needle 5 is a number of coiled springs 6,

each spring having a narrow central portion and outwardly tapering or outwardly curving end portions whose coils of maximum size approximate in diameter to the internal diameter of the vaporiser tube. The use of such a coiled spring per se is already known for guiding the needle or pricker rod but according to one feature of the present invention two or more (conveniently four as shown) such springs are employed mounted end to end within the vaporiser and compressed by the application of the end closure member or base 3 of the vaporiser. Preferably, the upper three springs are provided with washers 7 at their lower ends so as to assist their axial movement under compression. The form and disposition of the springs leaves a number of annular spaces of varying diameter between the exteriors of the springs and the internal walls of the vaporiser tube which spaces are packed with steel wool or similar filtering material 8.

The above described construction has proved considerably superior in operation to prior units, and this has been proved by actual comparative tests which showed that the invention materially reduced choking when leaded fuels were used.

While no exact theory of operation to explain the improved results will be advanced applicants believe that by providing tapered springs within the tube so surrounded by the filtering medium as to provide substantially coaxial, partially concentric passages with different resistances to fluid flow through the tube, more decomposition of the fuel takes place in the spaces 9 than in the filter elements so that most potential deposits form in those spaces and do not clog the filters. The pricker wire or needle 5 passes up through the centres of the springs 6, as already described, and this together with the strands of steel wool in the filters 8 which project inside the helices efiectively prevents any fuel passing up the vaporiser without going through the filter elements. This construction also has the advantage that the needle is centralised at relatively few points along its length. It has been found that if the needle is held in place, for example, along its entire length by being enclosed inside a narrow tube it very rapidly becomes firmly attached to this tube my gum or other deposits. In the present construction these deposits can only form at a few points in the length of the needle and not to an extent sufiicient to prevent its correct operation.

We claim:

A vaporizer for a pressure burner burning liquid fuel comprising a tube, a cap on one end of said tube and provided with a central jet orifice, a plurality of coiled springs axially disposed within said tube in abutting relationship, each of said springs having a narrow central portion and outwardly tapering end portions whose coils of maximum size approximate in diameter to the internal diameter of the tube whereby annular spaces are formed between the exteriors of the respective springs and the interior of the tube, a filtering medium for said liquid fuel packed inside said annular spaces to provide substantially coaxial, partially concentric passages with different resistances to iiuid flow through said tube, and a cleaning needle for said orifice, co-axial with the springs and passing through said narrow central portions thereof to be centralized thereby.

References Cited in the file of this patent UNITED STATES PATENTS 630,549 Moskowitz Aug. 8, 1899 1,466,417 Adamson Aug. 28, 1923 2,463,830 Tullis Mar. 8, 1949 FOREIGN PATENTS 537,392 Great Britain July 10, 1941 

